BEIJING (AP) — As big-city politician Bo Xilai rose to nationwide prominence with an anti-mafia crusade and mass sing-alongs of communist anthems, many of China‘sleaders trekked to his metropolis approvingly. Not President Hu Jintao.

Mr. Hu’s conspicuous absence from Chongqing, one of China‘s biggest cities, was telling. The charisma and self-promotion that made Mr. Bo popular with many Chinese at times alienated his political peers. On Thursday, the Communist Party sidelined Mr. Bo, removing him from his post as Chongqing’s Communist Party boss and highest-ranking official and likely ending his chances of promotion to the highest ranks of power that seemed within grasp only months ago.

Tall and telegenic, Mr. Bo is an anomaly that proves the rule in Chinese politics.

His confidence in public, bordering on flamboyance, and his ease with the media clashed with the low-key, collegial and bland style preferred by the Chinese leadership. Ever since charismatic, populist Mao Zedong mired China in poverty and political chaos, his successors have worked to make sure no one person would dominate. Instead, rule would be by consensus among members of a collective leadership. Mr. Bo was a threat to that balance.

“This proves that the Communist Party has accomplished dominance by a bureaucratic clique, rather than dominance by a strongman,” said Wang Lixiong, an activist for democracy and minority rights in Beijing. Such unity, Mr. Wang said, means the party will continue to protect its power and not undertake meaningful democratic changes. “The Communist Party is more stable, so reform becomes more hopeless.”

Mr. Bo’s removal comes as Mr. Hu and many in the senior leadership prepare to step aside and turn over power to a younger group of leaders. While Mr. Bo cannot be counted out — he retains his seat on the Politburo, a top decision-making body — it’s unlikely that party power brokers could agree to fill a top spot with a tainted if still popular figure.

“Comrade Bo is a man of character and he has a clear-cut stance in the way he does things. So there are sharply different comments about him and they go to extremes. There are those who love him and those who are extremely opposed to him,” Wang Haijiang, a Beijing lawyer and commentator, tweeted on Sina Corp.’s Weibo, a Chinese version of Twitter.

The trigger for Mr. Bo’s sidelining was a scandal that started last month when a trusted aide, Wang Lijun, who was the vice mayor and former police chief, suddenly fled to the U.S. Consulate overnight, apparently in a bid for political asylum. His flight to a foreign diplomatic outpost represented a major breach of discipline, jeopardizing secret information and bringing into public view the bare-knuckled infighting the leadership tries to keep under wraps.

Mr. Bo is being replaced in Chongqing by a vice premier who ran several prosperous provinces. In announcing his dismissal, the party made only glancing reference to the scandal, with the personnel chief saying the decision was made “after discrete consideration and based on current circumstances and the overall situation.”

But Mr. Bo was raising hackles long before the scandal broke. While commerce minister earlier last decade, he kept already overworked senior officials in their offices late to study the quotes of Mao until a retired predecessor asked him to stop.

The son of one of communist China‘s founding fathers, Mr. Bo took part in a violent Red Guard faction and was sent to jail for part of the radical 1966-76 Cultural Revolution. He went on to major in journalism in college before working his way steadily upward in the communist bureaucracy.

As a provincial official, he showed an early flair for publicity, drawing notoriety to the port city of Dalian with global gatherings, eye-catching urban renewal projects and the development of a vibrant high-tech sector.

He mailed copies of local government periodicals in which he figured prominently to national and international media.

It was in Chongqing — a sprawling city of 30 million — that he undertook his most ambitious projects, launching the signature campaigns that seemed designed to ensure his entry to the senior leadership in 2012.

The most prominent, the controversial “smash the black” anti-gang crackdown, resulted in 2,000 arrests, 500 prosecutions and 13 executions, including the former director of the city’s Judicial Bureau, and a wave of nationwide publicity. Then came a “sing red songs” campaign to praise the party and its values that reached a crescendo with mass sing-alongs commemorating last year’s 90th anniversary of the founding of the Communist Party.

Despite their popularity in Chongqing and elsewhere, criticisms emerged. Legal scholars accused Mr. Bo and Mr. Wang, as police chief, of ignoring due process. Private businesses grumbled they were being falsely accused in a bid for shakedowns.

Combined, Mr. Bo’s two campaigns smacked of the mass mobilization tactics of Mao.

“He opened up the risk of once more using mass movements and campaigns toward factional infighting inside the leadership,” said Francois Godement, China expert at the European Council on Foreign Relations.

In being sidelined, Mr. Bo’s popularity seemed undimmed among many who say his anti-gangland crackdown was a fitting response to China‘s pervasive corruption.

“Bo Xilai is down. The ones that are most happy are the gangs,” Yu Fenghui, a financial commentator, wrote on Sina Weibo. “Gangs across the country should drink all through the night to celebrate it today.”

For now, Mr. Bo remains in limbo, although observers say he likely will avoid formal reprimand. He could be assigned a powerless ceremonial position while retaining his privileges as part of a deal to avoid more inner-party turbulence.

The decisive handling of his case shows the might of the party’s personnel management system, while its built-in safeguards preventing the rise of a political strongman likely saved Mr. Bo greater humiliation, said Ding Xueliang, professor of social sciences at the Hong Kong University of Science and Technology.

“In the old days, under a powerful leader such as Mao, Bo would have been simply crushed to bits,” Mr. Ding said.